The present invention relates to an apparatus for generating an operation voltage of a non-volatile memory device. More particularly, the present invention relates to an apparatus for generating a voltage for controlling an output voltage, of which a voltage level is not limited, in accordance with ambient temperature and a non-volatile memory device having the same.
A flash memory device as one of a non-volatile memory device includes typically a plurality of strings, wherein one string has memory cells connected in series.
The flash memory device is widely used in various semiconductor devices such as a laptop, a personal digital assistant PDA, a portable electrical device, e.g. portable phone, a printer, an universal serial bus USB driver, etc.
Generally, in a memory cell array of the flash memory device, memory cells are connected in series between a bit line BL and a cell source line CSL.
A NAND-flash memory device includes a drain source transistor DST and a source selective transistor SST so as to connect electrically a memory cell to the bit line BL and the cell source line CSL.
The non-volatile memory device uses a multi level cell MLC for storing data of plural bits so as to increase storage capacity of the data.
That is, since one memory cell stores the data of the plural bits, storage capacity of the non-volatile memory device is increased. However, since many threshold voltage distributions exist when the memory cell is programmed, a time to be taken for the programming has been increased. Accordingly, various techniques for reducing the time have been developed.
On the other hand, a threshold voltage of the memory cell in the non-volatile memory device is changed depending on a temperature. Hence, the threshold voltage of the memory cell may be considerably changed due to a difference of a temperature when the memory cell is programmed and a temperature when the data is read. Accordingly, data may be erroneously read in case of reading the data on the basis of a predetermined read voltage.
The above information disclosed in this Background section is only for facilitating understanding of the background of the invention and may not constitute prior art.